The oscilloscopes are started with <o> and come in 4 different modes:
logical (the channels are sorted with the default panning position),
phyisical (channels 1 to n from top to bottom), master (the mixed output
channel(s)) and single (the currently selected channel is shown).

By pressing <tab> you can enable/disable triggering of the scopes. If
the output is triggered a wave on the screen always starts with the upper
halvwave. If triggering is turned off the wave will be drawn from the
current position.